A hybrid, coupled reactors based 18-pulse diode rectifier with active power filter

The paper presents the study and selected results of simulations and laboratory tests of the hybrid system with 18-pulse rectifier with coupled reactors and small active power filter. The comparison of systems with series and shunt active power filter is given. The system makes it possible to reduce, especially in distribution supply networks, undesired higher current harmonics. The 18-pulse nature of operation of the rectifier is reached using a set of coupled three-phase network reactors. Simultaneous use of the coupled reactors and the small active power filter provides opportunities for reduction of the supply current distortion, especially in case of voltage harmonic distortion and voltage unbalance.